Grinding apparatus.



H. K. HITCHCOCK.

,summum manna. v nruorrlol rlLnn .univ 19, 1901. nnrzwnn Jpn 12,1909. In y 934,442. rammed spfh 21M, 1909i v/ 4 i x 11i.; ze f5 i 'Il i Lk`cocu. a eitizen o'l the United HALBEBT K. HITCHCOCK. F TAENTUM,PENNSYLVANIA.

@BINDING APPARATUS.

Specification of Letters Patent..

` Application le'd July 19. 1907, Serial No. 384.639; Renewed July 12,

Patented Sept. 21, 1909.

1909. 'serial No. 501,259. i

yTo all 'whom i may confer-n:

Ilrrcix- States., residing at 'I`areutum. in the eounty of Allegheny andState of Pennsylvania. have invented certain new and useful Improvementsin tirindizrer Apparatus. of which the following is a speeitieatton.

.ily invention relates to griruiingir apparatus. and has for itsprincipal objects: to provide au apparatus wherefhy the rapidity of thereducing operation is accelerated, and u ithout any wast e of theahrading material; to provide an apparatus wherein ahrading material ofa degree of tineness varying to -uit the kind of grinding done isautomatit-ally supplied in eonjunetion with the proper amount of waterntacessary for eaeh partienho: operation: and finally. to provide anappwatus' reduit-im;t little-attention. wherein the :thrusting materialis act'urateiy graded and supplied in proper quantities directly tromthe grading meansy to the grinding mechanism. (')ne embodiment of myinvenle it. known thatl. H tLm/:u'r K.

tion is illustrated in the aeeompanying draw ings. wherein :A--

'fig-uw t is a side elevation partly in seetnm shim ing the relativearrangement ot' the nat-ts. and i Figure is a plan view of theapparatus. The apparatus illustrated and hereinafter hv-erihed. isdesigned fin' the operations iu- -ident to the grinding and smoothing ofplate glass. hut it will he understood that the hroatl inventioninvolved is applienhle to a .title rang't ot grinding' operatious. lnthe apparatus illustrated` the invention relates pa 'tiental-lv to themeans .for supplying hrading' material. the grinding meellanism 'wedlit-ingr suhstantially the same. as that .:-retot'ore employed.lleretofore the Sand ast-d io glass grinding has been handled asmtl-Jus. For the rough reduction oi' the surtaetof the glass. orvfacing; operation. a mixture ot' ,Land containing hoth coarse and tinematerial was placed in a long: V shaped hoppt-i adjat'ent. the grindingrtahle and washed thereon h v a stream of water from a hose. lu thisoperation the finer. lighter material was washed out first leaving theeoarser material to he used last. This operation has heen foundunetzonomieal. as the use of the eoarse aand last leaves the glass witha very rough finish. necessitating.r a long and tedioueI Furthersand ardwatef;

subsequent. finishing operation. more, the character of the "in'gmaterial into its various cannot he accurately kgagged and the sand actsto poor' advantage when eoarser and finer partieles are upon the tableat the same time, as the coarser particles keep therunners from touchingthe .finer particles and the finer particles get in the way of thecoarser ones and impair their effectiveness. For the finishingroperation, the ahrading utaterial was then separated into grades ofvarying fineness either by means of a settling procese@ wherein thewater from the facing operation carrying the abradinv material insuspensiotnwas carried through a series of pits' or tanks wherein thevarious grades set tied, or by an additional water carrying thealu-ailing material in snspension was placed in a tank and agitated,after which the abrading material was allowed to settle. "for a givenperiod and the mixture above a 'certain level Withdrawn,

whieh operation was followed hy a Seriesof additions ot water,agltattons, withdrawals' and settlings of the volumes withdrawn, thusgradually eliminatingthe li hter parts of thematerial trom the tank ansettling them. While the addition of the. second method lgives hetterresults than the first, both are inconvenient in operation and givegrades lacking in uniformity. as the result of the separation varieswith the mixture introduced. which mixture'is a variable one and cannot.he gagged with any certainty. and in any ease the separation isincomplete due to the entrapping; ol' quantities ot the liner materialheneath that which is eoarser. lt will process wherein.

he seen that the foregoing operations re quired a great deal of labor inrehandling the ahradiug' material after grading it. eonvcyinp; it to thegrinding mechanism and gauging its applit-ation to the grinding'meehanism. and the operation was accompanied hy a wasttl of material andan inefficient operation ot' the -grindingr mechanism. My improvedapparatus is designedto aeromplish the desired separation into aninfinite umidita-'of grades completely and aeeuratetv withoutrehaudling. and to supply suclrmiv terial to the grinding mechanismdireetly.'

and in tuantities adjusted to suit the condition o the surface to hereduced. beginning with the eoarsest and followingrup with successivelyt'mer and liner grades. dated. the, apparatus comprises the usualIgrinding mee lanism in conjunction with ,a sgi-ailing tank adapted toseparate the ahradgrades and so Briefiy is largest take the lowest.positions. as the' normal down 'ard veloeitv ot a particle through thewater depends upon this ratio. which ratio in particles ot' the sameshape and density increases'with the size ot' the particles. 'l`lictargetand more compact particles thus como to a position ofequililiriutn in a stratum in the bottom ot' the tank where the upwardvelocity is `greatest. whih` the other particles arrange themselves in aseries otl st rata. the ratios ot' weight'to resistance in liquid of theparticles composing which strata. decrease 'as the distance from ,thebottom oi' the tank increases. A tter the material has heen graded. thecontents oll the tank is drawn ott' from the.hotto!n. thus sftpplvcg thecoarsest material in the tahlo to do the rough l lfrindiug. and as thesurface of the glass is reduced. a liner and tim-r qualit)` ot' materialis supplied until all the material has heen withdrawn from the tank andthe plate under treatment has been reduced to the required degree olsmoothness.

Referring now to the drawinfr, the appaiatus hown at the lett of thehgures is the ordinary grindingr mechanism. for reducing the surface ot'plate glass. while the apparatus shown at4 the right of the figures isthe rial to the friuding apparatus wherein my invention particularlyresides. The grinding mechanism comprises the usual table l .on thesurface ol which the glass is secured, the shafty 2 for turning suchtable. the gear :t t'or driving the shaft 2` the. runners or grindingdisks -l supported ahove the table 1 in position to grind the t'ace ofthe glass in the usual manner, and the shafts 5 for carrying therunners. which shafts 5 are mounted in a frame-work capable of lateralmovement to permit of the removal of the glass. l is the usual troughe\tendinr about the tahle in position to receivetho ai-i tcrial and4'atei' as it falls t'rom the table, and 7 is the drainage pit intowhich the abrading material and water from the trough 6 is collected.The gradino' a paratus comprises the tank S pret'erahlY o the conicalshape shown` provided with' the overflow pipe 9 and the inlet, pipe 10,which inlet pipe is provided with a cut-ott' valve 11. 65 ho contents ofthe tank are condulzjted to means for grading and supplying the n1ate`raiding nia-- ried in the receptacle 15"', which receptacle y nconstructed with downwardly '.:onverging walls. and is adapted to helled 'from the mam h v means of the cock 15p,

.steam pipe 16 is provided with an upwardly directed end 1T adjacent thelower end' ot' gradually tht` admission pipe .ltt which constitutes ameans for securingr a llow ol' liquid from the pit T up into and throughthetank I- The operation ot' the, apparatus 1s as fol; lows. 'lhe pit.being tilted with a mixture ot' ahrading material and water from thefacing operation. stea'm is admitted te the pipe 1 thus sending a streamof liquid upward through the pipe 10 and the.tank-S. This tlow iscontinued until a proper density ol' liquid in the tank S is secured.the surplus water together with the particles of material in themixture. too tine to use. overtlowing through the pipe 9 and leaving inthe tank the heavier portions designed 'for use in the grindingoperation. A stratification ot' the particles of material in the tankoccurs with thel la rger and heavier particles at the hottom and thesmaller particles arranged thereahove in positions depending.' upontheir size. density and frictional Surface, which result is securedhecauseoi' the difference in the upward velocity of the' liquid in thetank at the dill'erent levels and liecanse of the fact, that the ratioof the weight. of the .particles to their frictionat surface increaseswlth their size and density.` The point of greatestvelocity of upwardflow in the tank Sis obviously at. the bottom for two reasons. first,because of the increased cross-section of the tank as the asipiterprogresses npward, rendering such vel/deity inversely proportional tothe'area, and. seeond, hecause of the fact that the larger particles atthe lower levels crowd Vcloser tolsettler than do the particles attheupper levels. thus reducing the amount of sp het ween the particles.tween the particles at the inter space velocityof course increases. .-othat even in a tank which did not have converging walls, the nter'spacevelocityfatr the lmttom would be greater than .at the top. After thetank vhas been filled tothe required density, which may be determined hya hydrometer, or byv any *other desired means, vthe flow of steamthrough the pipe ttt; ehrt ott, the valve 1l closed and the d1 y.iikandL are opened, thus RCP As the total'space ifi/gg` any level decreasesft-:J

f tank 8 has permitting the mixture of abrading material and wait-er inthe tank 8 to tlow to the grinding mechanism, while a stream o f water.through the pipe 14 is introduced i ii order to maintain in suspensionthe particles already in equilibrium in the tank, and to carry to theirproper sitions the finer material last introduce grinding mechanism isof course started to operate at the time the valve 13 is opened und thevalve 13 may be turned .to supply precisely the amount of abradinmaterial necessary. It will be seen that t c coarser material issupplied first to the grindig mechanism, and, as the surface is reduc afiner and finer grade of material is supplied, which operation continuesuntil t glass is properly faced and finished. As the tank empties, thevalve 15 'is' gradually closed by reason of the filling of the tank 152from the cock 15s and the raising of" the float 15. The reduction of theflow from the pipe I4 permits the finer grades of sand to settle to thebottom of the tank and discharge, and at the same time prevents theproportion of water to abrasive from becoming too great. The valve 15 mabe adjusted to supply the mixture of a rasive and water which ma hefound most efficient for the work to be one.

It will be apparent from the foregoing that by the use of my apparatusno additional handling of the abrading material after grading isnecessary, and that after the been filled and the valves 13 and 15opened, the supplying of material to the grinding mechanism is entirelyautomatic.

t will also be seen that the material supplied is very accurately graded.with all particles having the same physical characteristics .arrangedtogether', and that the various grades of material are grindingmechanism in proper order and with the proportion ot' water necessary toeffect the best results. The forni of tank shown although the preferredone, is not essential to the operation of the apparatus, und if desired,the material might be dumped into the top of the tank instead of drawnfrom the drainage pit 7, the water from the main 14 being depended uponto secure the proper arrangement of the particles in the tank. Thesupply of water from the main 14 may of course be controlled manually ifdesired, and in case the apparatus is usedfor finishing and the abrasiveis very fine, the tlow of water from the main may be omitted andtheabrasive allowed to grade by settling without the assistance of theupward flow. Various other modifications which will' be apparent tothose skilled in the art, might be made without departing from myinvention :is defined by the claims.

Having thus described my invention and illustrated its use, what Iolainifas new and into the tank. Thel weight.

supplied :to theA downwar of water upward vthe abradin desire to secureby Letters Patent is the followin 1. pparatus for 'supplying abrasive torinding or smoothin mechanism, comprising in combination with amechanism using an abrasive with'water, a grading tank pro= vided withdischarge means in h in position to rmit of discharge to the saidgrinding mec ianism, and means for securing an upward flow ofliquidtlirough the tank, whereby the articles of abi-siding material aresuspende in different strata at positions depending u on the ratio oftheir resistance in the liqui to their weight.

2. Apparatus for supplying abrasive to grinding or snioothng mechanism,comprising in combination with a mechanism using an abrasive with water,a grading tank provided wit-h downwardly converging walls and having adischarge )tissage at its lower end above theisaid mechanism, and mea-nsfor securing an upward tiow of liquid the lower end through the tank,whereby the particles of abrading material-are suspended in diii'erentstrata at positionsdependlng upon the ratio of their resistance in theliquid to their 3. Apparatus for supplying abrasive to grinding orsmoothing mechanism, comprising in combination willi a mechanism usingabrasive with water, a conical gradingr tank having a discharge passageat its lower end adjacent the said mechanism, and means for securing anupward flow of water through thetank, whereby th'cparticles of abradingmaterial are suspended in different strata at positions depending uponthc ratio of their resistance in the liquid to their weight.

4. Apparatus for supplying abrasive to grinding or smoothing mechanism,rannprising in combination with a mechanism using an abrasive with waterand having n drainage pit, a grading tank provided with downwai-diyconverging walls. a discharge pussage leading from thc'lower portion ofthe tank to the saidmechanism. an admission passage leading .from thepit. to the bottoni ofthe tunlnand means for securing a tiow of liquidup through such lust passage and the tank.

5. Apparatus forA supplying abrasive to grinding and smoothingmechanism.v coniprising iii4 combination with a mechanism using anabrasive with water and haring a drainage pit, a grading tank providedwith passage. loading from thc lower portion Aof the tank to the saidmechanism, an admission passage leading fronitlie pit to the bottom ofthe tank. means for securing a flow of liquid up throughsnch .lastpassage and the tank, and a Vwater ipe forsecuring a ow t rough the tankto hold material in si'ispensitm when the flow of liquid from the pit iscut oil'.

ly converging walls, a discharge 6. Apparatus for supplying abrasive tof {rindingf` or smoothingr mechanism. comprising in combination with amechanism using an abrasive with water. a gradita,Y tank ha vin;`do'tviiwai'dlv converging walls above the table. a paisage leading' fromthe lower end of the taiik to the said mechanism and means for securingan upward iow of liquid from the bottom ofthe tank. whereby thevparticles of abiadingg;` material are suspended in different strata atpositions depending upon the ratio of their resistance in the liquid totheir weight..

7. Apparatus for supplying abrasive to grinding or smoothing mechanism.comprising in combination with a mechanism using an abrasive iii water,a grading ltank having a discharge passage at its lower end inpositionto .discharge to the said mechanism, means for securing an upward tlowof liquid through thel tank and automatic ins-ans' for graduallycuttingr oli' the said upward flow as the tank empties through the saiddiseliarge. passage.

51. Apparatus for supplying abrasive to grinding or smoothingmeohai'iisni comprising in combination with a mechanism using'` anabrasive with water, a grading tank havingga discharge passage at itslower end in position to discharge to the said mechanism, means forsecuring an upward flow of liquid through the tank and automatic meansfor cutting otl' the said upward tiow at. a decreasing rate as the tanken'ipties through the said discharge passage. 4

9. Apparatus for supiilyiiig abrasive to grinding or smoothingmechanism, comprising in' combination with a mech-.mism using anabrasive with water, a grading tank having a discharge passage at itslower end in position to dischargeto the said mechanism, means forsecuring an upward tlow of liquid 4througih the tank, a valve forcontrolling such tiow, a float for operating the valve, a receptacle forthe. tioat and means for gradually filling the receptacle as the. tankempties through the said discharge passage. l

-10. Apparatus for supplying abrasive to grinding or smoothingmechanism. comprising in combination with a mechanism using' an abrasivewith water, grading tank having a discharge passage at its lower end inlmsition 'to discharge to the said mechanism, means for securin,"r anupward flow of.li. ;uitl through the tank. a valve for controlling suchtluw. a float. for operating the valve. a

yreceptacle for the tloatl having dowiiwardhr the other grades in theorder of the size of the particles comprising the grades.

lf2. Apparatus for supplving abrasive to grint'liitg or smoothingmechanism. comprisint; in combination with a. inet-,lianisiii using anabrasive with water, a grading tank in position to discharge thereto,means for carrying abrasive iii suspension to the tank. and meanswherebythe abrasive is maintained in suspension in the tank until discharged tothe gifi'indiinglr mechanism.

13. Apparatus toil supplying abrasive to grinding or Smoothing:mechanism.' comprising'in combination .'itli a niechaniz-au using anabrasive. wit-li water, a grading tank in position to discharge thereto,means for carryingr abrasive iii suspension to the tank, means wherebythe abrasive is maintained iii suspension iii thel tank until dischargedto the said mechanism and means whereby the proportion of abradingmaterial to iva-- ter may be varied.

In testimony whereof 1 have hereunto signed in v naine. in the. presenceof the two' subscribed witnesses.

HALBERT K. HITCHttKlK. i

Witnesses l". E. (Ai'riiiiii, Aiiciiwoic'iii MARTIN.

ing in combination with a mechanism using l

